1) First create your main.fla document and write code and base classes.

2) Then go to Publish Settings and select Export SWC option in the Flash tab.

3) Compile your movie. This will also generate an swc file.

This is an only one time process.

The for each Module:

1) Now create your module.fla document in a separate folder to avoid including base classes.

2) Go to the Publish Settings -> Flash tab -> Script Settings… -> Library Path.

3) Here you must add another library by pressing the plus (+) sign and then the “browse to SWC file” button (the one with an f in the icon).

4) Browse to the SWC file generated by the main.fla.

5) Once the SWC file is added, click the plus sign (+) beside it to open more options.

6) Double click the first option “Link Type…”

7) In the popup that opens select External as “Link Type”. External means the code will not be included in the SWF file and will not be loaded as an RSL either. You have to add this classes manually either by loading an SWF file or by loading the Module into another SWF file with this classes.

Close everything with the OK button and that’s it. This is a one time process for each Module.

Then, whenever you change the base classes in your main flash you’ll have to compile the movie again, and then recompile the modules as well.